Double Row Cylindrical Roller Bearing NNU4938/4940 B/Sp W33 for CNC Machine Tools

Product Specifications

Application Industries

Minimize CNC Downtime with Precision NNU4938/4940 Double Row Cylindrical Roller Bearings

CNC machine operators know the frustration of unexpected spindle failures—hours of production lost, missed deadlines, and costly repairs. When bearings fail prematurely due to poor quality or incorrect specifications, the impact ripples through your entire operation. Sourcing reliable, high-precision bearings often means coordinating with multiple suppliers, each with different lead times and quality standards.

Authentic Double Row Cylindrical Roller Bearings, In Stock for Immediate Delivery

Our NNU4938/4940 B/Sp W33 Double Row Cylindrical Roller Bearings are engineered to meet the rigorous demands of CNC machine tool spindles. As an officially authorized distributor, we guarantee 100% authentic products with full traceability. With sufficient ready stock of P4/P2 precision grade bearings, we can deliver these critical components when you need them most, eliminating long lead times that delay your production.

Engineered for High-Precision CNC Machine Tool Performance

These Double Row Cylindrical Roller Bearings excel in applications requiring high radial load capacity and precise axial alignment—key requirements for CNC machine tool spindles operating at high speeds. The separated design allows for easy mounting and dismounting, simplifying maintenance and reducing downtime. Their non-aligning特性 ensures stable performance even under varying operating conditions, making them ideal for the continuous, heavy-duty cycles of modern manufacturing.

Technical Features That Ensure Reliable CNC Operation

The 60-64 HRC hardness of the bearing steel provides exceptional wear resistance, extending service life in high-stress environments. Available clearance grades (C0, C2, C3, C4, C5) allow precise matching to specific spindle preload requirements, balancing rigidity and heat generation. Cage options in brass or steel cater to different speed and load conditions—brass cages offer superior strength for heavy loads, while steel cages provide stability at higher rotational speeds. Vibration classes Z1V1 to Z3V3 ensure quiet operation, critical for maintaining precision in sensitive machining processes.

Why Authentic Bearings Matter for Your CNC Investment

Counterfeit bearings may save money upfront, but they often fail prematurely, leading to unplanned downtime and potential damage to expensive CNC spindles. The true cost includes not just replacement parts but also lost production, maintenance labor, and compromised workpiece quality. Our bearings comply with ISO 9001 and DIN standards, undergoing strict quality control from incoming material verification to finished product delivery. This commitment to quality ensures consistent performance and reduces the total cost of ownership over the bearing's lifecycle.

Trusted by CNC Manufacturers Worldwide

Packaging & Shipping

• Carton pallet packaging designed to protect bearing precision during transport
• Rapid delivery from ready stock for urgent maintenance needs
• Global logistics options including express, air, and sea freight
• Real-time full logistics tracking for complete supply chain visibility
• Flexible order quantities, including single-unit purchases for emergency repairs

Secure Your CNC Spindle Performance Today

Don't let bearing issues disrupt your production schedule. Whether you need replacement bearings for scheduled maintenance or emergency repairs, our NNU4938/4940 Double Row Cylindrical Roller Bearings are ready to ship. The longer you wait, the more production time you risk losing—act now to keep your CNC machines running at peak efficiency.

Frequently Asked Questions